Add cpu_target variant to openblas (#5090)

var/spack/repos/builtin/packages/openblas/package.py

@@ -51,6 +51,10 @@ class Openblas(MakefilePackage):
     variant('openmp', default=False, description="Enable OpenMP support.")
     variant('pic', default=True, description='Build position independent code')
 
+    variant('cpu_target', default='',
+                    description='Set CPU target architecture (leave empty for '
+                        'autodetection; GENERIC, SSE_GENERIC, NEHALEM, ...)')
+
     # virtual dependency
     provides('blas')
     provides('lapack')
@@ -108,8 +112,12 @@ def make_defs(self):
             'FC={0}'.format(spack_f77),
             'MAKE_NO_J=1'
         ]
+        if self.spec.variants['cpu_target'].value:
+            make_defs += [
+                'TARGET={0}'.format(self.spec.variants['cpu_target'].value)
+            ]
         # invoke make with the correct TARGET for aarch64
-        if 'aarch64' in spack.architecture.sys_type():
+        elif 'aarch64' in spack.architecture.sys_type():
             make_defs += [
                 'TARGET=PILEDRIVER',
                 'TARGET=ARMV8'